Somewhere, someone is tweeting “[This airline] sucks the big one!” In the past, they would have been ignored. These days many airlines respond with sympathy (“We're so sorry you’re having a rough trip -- please DM us, so we can resolve it”) or send an invitation to call an 800-number (where you can wait on hold forever).

A tool called sentiment analysis, or the mathematical categorization of statements' negative or positive connotations, gives companies powerful ways to analyze aggregate language data across all sorts of communications, not only tweets. There's real value in measuring sentiment inside and outside your company. Here are five of the most valuable sentiment sources to tap.

Customer inquiries

When a customer asks about your product or services, metrics on overall sentiment, the length of the message, and words used can be compared to past inquiries. Different inquiries warrant different treatment.

Customer service

When a customer writes in about a problem, is he or she really upset or simply asking, “Hi, can you look into this?” Sentiment analysis of these interactions helps track the way customers feel about your company or product over time. Is your relationship solid? When interacting with an inexperienced operator, do customers walk away satisfied?

Employee interactions

When employees talk, are they happy? Satisfied? Also, do certain employees spread unhappiness and dissatisfaction? You’re already scanning emails for Trojans and IP violations, why not for emotions? Whether this is email, Slack, or some other chat tool, communication and sentiment scores can be useful tools to learn how employees are feeling and how likely they are to leave.

HR interactions

When HR gets involved, what are the interactions like? Do they settle the issue or do employees walk away upset? Happy employees are more likely to stay or at least less apt to sue.

News and public data

This is particularly useful for large, public companies. Sure, your PR company sends you a list at the end of the month, but is your news trending positive or negative over time and on what topics?

By looking at these data sets, you can strengthen your marketing and PR operations, possibly improve employee retention, and ultimately improve customer service. Sentiment analysis is readily available and easily accessible to most developers. It offers a powerful avenue to quantify the success of your business and use data science to improve it.